Electrochemical detection of arsenic(III) completely free from noble metal: Fe3O4 microspheres-room temperature ionic liquid composite showing better performance than gold.

In recent decades, electrochemical detection of arsenic(III) has been undergoing revolutionary developments with higher sensitivity and lower detection limit. Despite great success, electrochemical detection of As(III) still depends heavily on noble metals (predominantly Au) in a strong acid condition, thus increasing the cost and hampering the widespread application. Here, we report a disposable platform completely free from noble metals for electrochemical detection of As(III) in drinking water under nearly neutral condition by square wave anodic stripping voltammetry. By combining the high adsorptivity of Fe3O4 microspheres toward As(III) and the advantages of room temperature ionic liquid (RTIL), the Fe3O4-RTIL composite modified screen-printed carbon electrode (SPCE) showed even better electrochemical performance than commonly used noble metals. Several ionic liquids with different viscosities and surface tensions were found to have a different effect on the voltammetric behavior toward As(III). Under the optimized conditions, the Fe3O4-RTIL composites offered direct detection of As(III) within the desirable range (10 ppb) in drinking water as specified by the World Health Organization (WHO), with a detection limit (3σ method) of 8 × 10(-4) ppb. The obtained sensitivity was 4.91 μA ppb(-1), which is the highest as far as we know. In addition, a possible mechanism for As(III) preconcentration based on adsorption has been proposed and supported by designed experiments. Finally, this platform was successfully applied to analyzing a real sample collected from Inner Mongolia, China.

[1]  Ewa Rozniecka,et al.  Electroactive ceramic carbon electrode modified with ionic liquid , 2005 .

[2]  Xingjiu Huang,et al.  Stripping voltammetry study of ultra-trace toxic metal ions on highly selectively adsorptive porous magnesium oxide nanoflowers. , 2012, The Analyst.

[3]  Richard G Compton,et al.  A comparison of different types of gold–carbon composite electrode for detection of arsenic(III) , 2005, Analytical and bioanalytical chemistry.

[4]  Jinhuai Liu,et al.  Toward Membrane-Free Amperometric Gas Sensors: An Ionic Liquid–Nanoparticle Composite Approach , 2011 .

[5]  D. Macfarlane,et al.  Pyrrolidinium Imides: A New Family of Molten Salts and Conductive Plastic Crystal Phases , 1999 .

[6]  John H T Luong,et al.  Electrochemical determination of arsenite using a gold nanoparticle modified glassy carbon electrode and flow analysis. , 2006, Analytical chemistry.

[7]  T. Ohsaka,et al.  Anodic Stripping Voltammetric Detection of Arsenic(III) at Gold Nanoparticle‐Modified Glassy Carbon Electrodes Prepared by Electrodeposition in the Presence of Various Additives , 2008 .

[8]  J. Aggett,et al.  The determination of arsenic(III) and total arsenic by atomic-absorption spectroscopy. , 1976, The Analyst.

[9]  R. Compton,et al.  Simultaneous Detection of Trace Cadmium(II) and Lead(II) Using an Unmodified Edge Plane Pyrolytic Graphite Electrode , 2011 .

[10]  I. Ali,et al.  ARSENIC: OCCURRENCE, TOXICITY AND SPECIATION TECHNIQUES , 2000 .

[11]  Dongfang Cao,et al.  Electrochemical biosensors utilising electron transfer in heme proteins immobilised on Fe3O4 nanoparticles. , 2003, The Analyst.

[12]  R. G. Evans,et al.  Non-haloaluminate room-temperature ionic liquids in electrochemistry--a review. , 2004, Chemphyschem : a European journal of chemical physics and physical chemistry.

[13]  R. S. Sadana.  Determination of arsenic in the presence of copper by differential pulse cathodic stripping voltammetry at a hanging mercury drop electrode , 1983 .

[14]  W. Holak.  Determination of arsenic by cathodic stripping voltammetry with a hanging mercury drop electrode , 1980 .

[15]  H. Leu,et al.  A Fe3O4-Based Chemical Sensor for Cathodic Determination of Hydrogen Peroxide , 2005 .

[16]  Jinhuai Liu,et al.  O2-plasma oxidized multi-walled carbon nanotubes for Cd(II) and Pb(II) detection:Evidence of adsorption capacity for electrochemical sensing , 2011 .

[17]  Richard G Compton,et al.  Toward membrane-free amperometric gas sensors: a microelectrode array approach. , 2010, Analytical chemistry.

[18]  Xiu‐Ping Yan,et al.  On-line coupling of capillary electrophoresis to hydride generation atomic fluorescence spectrometry for arsenic speciation analysis. , 2002, Analytical chemistry.

[19]  Angelo Albini,et al.  Multiwalled carbon nanotube chemically modified gold electrode for inorganic As speciation and Bi(III) determination. , 2006, Analytical chemistry.

[20]  H. Khani,et al.  Multi-walled carbon nanotubes-ionic liquid-carbon paste electrode as a super selectivity sensor: application to potentiometric monitoring of mercury ion(II). , 2010, Journal of hazardous materials.

[21]  P. H. Davis,et al.  Determination of total arsenic at the nanogram level by high-speed anodic stripping voltammetry , 1978 .

[22]  Richard G Compton,et al.  Analytical methods for inorganic arsenic in water: a review. , 2004, Talanta.

[23]  A. Salimi,et al.  Electrochemical detection of trace amount of arsenic(III) at glassy carbon electrode modified with cobalt oxide nanoparticles , 2008 .

[24]  Xingjiu Huang,et al.  High adsorptive γ-AlOOH(boehmite)@SiO2/Fe3O4 porous magnetic microspheres for detection of toxic metal ions in drinking water. , 2011, Chemical communications.

[25]  J. Castillo,et al.  Direct reduction of As(V) physically attached to a graphite electrode mediated by Fe(III) , 2007 .

[26]  J. Luong,et al.  Biosensor for arsenite using arsenite oxidase and multiwalled carbon nanotube modified electrodes. , 2007, Analytical chemistry.

[27]  G. Swain,et al.  Development of a method for total inorganic arsenic analysis using anodic stripping voltammetry and a Au-coated, diamond thin-film electrode. , 2007, Analytical chemistry.

[28]  J. T. Mayo,et al.  Low-Field Magnetic Separation of Monodisperse Fe3O4 Nanocrystals , 2006, Science.

[29]  P. Kulesza,et al.  Electrocatalytic oxidation and determination of arsenic(III) on a glassy carbon electrode modified with a thin film of mixed-valent ruthenium(III, II) cyanide , 1984 .

[30]  R. Compton,et al.  Particle Size and Surface Coverage Effects in the Stripping Voltammetry of Silver Nanoparticles: Theory and Experiment , 2008 .

[31]  B. Jena,et al.  Gold nanoelectrode ensembles for the simultaneous electrochemical detection of ultratrace arsenic, mercury, and copper. , 2008, Analytical chemistry.

[32]  Xingjiu Huang,et al.  Selective adsorption toward toxic metal ions results in selective response: electrochemical studies on a polypyrrole/reduced graphene oxide nanocomposite. , 2012, Chemical communications.

[33]  J. Zen,et al.  Flow injection analysis of an ultratrace amount of arsenite using a Prussian blue-modified screen-printed electrode. , 2003, Analytical chemistry.

[34]  Fangqiong Tang,et al.  A practical glucose biosensor based on Fe(3)O(4) nanoparticles and chitosan/nafion composite film. , 2009, Biosensors & bioelectronics.

[35]  M. Grätzel,et al.  Hydrophobic, Highly Conductive Ambient-Temperature Molten Salts. , 1996, Inorganic chemistry.

[36]  X. Yan,et al.  Determination of (ultra)trace amounts of arsenic(III) and arsenic(V) in water by inductively coupled plasma mass spectrometry coupled with flow injection on-line sorption preconcentration and separation in a knotted reactor. , 1998, Analytical chemistry.

[37]  G. Forsberg,et al.  Determination of arsenic by anodic stripping voltammetry and differential pulse anodic stripping voltammetry , 1975 .

[38]  T. Ivandini,et al.  Electrochemical detection of arsenic(III) using iridium-implanted boron-doped diamond electrodes. , 2006, Analytical chemistry.

[39]  A. Salimi,et al.  Boron doped diamond electrode modified with iridium oxide for amperometic detection of ultra trace amounts of arsenic(III) , 2004 .

[40]  Bin Fang,et al.  Fabrication of Fe3O4 Nanoparticles Modified Electrode and Its Application for Voltammetric Sensing of Dopamine , 2005 .

[41]  J. Wadhawan,et al.  Electrochemical detection of as(III) via iodine electrogenerated at platinum, gold, diamond or carbon-based electrodes , 2004 .

[42]  S. Adeloju,et al.  Constant current cathodic stripping potentiometric determination of arsenic on a mercury film electrode in the presence of copper ions , 1999 .

[43]  Dennis C. Johnson,et al.  Pulsed voltammetric detection of arsenic(III) at platinum electrodes in acidic media , 1992 .

[44]  P. Smedley,et al.  A review of the source, behaviour and distribution of arsenic in natural waters , 2002 .

[45]  Emma Muñoz,et al.  Analysis and speciation of arsenic by stripping potentiometry: a review. , 2005, Talanta.

[46]  S. Kounaves,et al.  On-site analysis of arsenic in groundwater using a microfabricated gold ultramicroelectrode array , 2000, Analytical chemistry.

[47]  Xuan Dai,et al.  Anodic stripping voltammetry of arsenic(III) using gold nanoparticle-modified electrodes. , 2004, Analytical chemistry.

[48]  Richard G Compton,et al.  Sonically assisted electroanalytical detection of ultratrace arsenic. , 2004, Analytical chemistry.

[49]  S. Pandey.  Analytical applications of room-temperature ionic liquids: a review of recent efforts. , 2006, Analytica chimica acta.

[50]  G. Swain,et al.  Total inorganic arsenic detection in real water samples using anodic stripping voltammetry and a gold-coated diamond thin-film electrode. , 2007, Analytica chimica acta.

[51]  C. Banks,et al.  The Electrochemical Detection of Arsenic(III) at a Silver Electrode , 2005 .

[52]  A. Bond,et al.  Liquid chromatography-electrochemical detection of inorganic arsenic using a wall jet cell with conventional and microsized platinum disk electrodes , 1990 .

[53]  M. R. Rahman,et al.  Selective detection of As(III) at the Au(111)-like polycrystalline gold electrode. , 2010, Analytical chemistry.

[54]  A. Ivaska,et al.  Applications of ionic liquids in electrochemical sensors. , 2008, Analytica chimica acta.

[55]  Kazuo T. Suzuki,et al.  Arsenic round the world: a review. , 2002, Talanta.